Not every technology entrepreneur has a coat of arms. But Ken Olisa is not the usual City grandee. With pride he shows the Olisa heraldic shield – a medieval-style crest with a design of red diamonds and green stars crowned by a red lion, and the motto "Do Well, Do Good".

The motto fits perfectly with his philosophy that successful businesses should give something back. Olisa, 61, is the founder and chairman of Restoration Partners, a merchant bank that provides advice to technology firms. He is also a philanthropist with a keen interest in education, and he wants to force reform of how the City of London does business, demolishing the gentleman's club-style boardroom culture and opening up companies to greater scrutiny.

Olisa knows what he is talking about. In 2011 he was ousted from the board of ENRC, the FTSE 100 Kazakh mining firm, in a notorious boardroom coup masterminded by the company's dominant oligarch shareholders. Olisa declared the company was "more Soviet than City", a phrase he has now trademarked – a tongue-in-cheek gesture, he says.

ENRC was rocked by disputes because the founding shareholders wanted to retain control of the business. "It was a power struggle over who was in charge of the company … and unfortunately a lot of value was destroyed in that fight," he says.

He was unimpressed with the "shareholder spring" of 2012 when investors forced the resignation of a number of bluechip chief executives. "It was a fund managers' spring, not a shareholders spring," he says. "It wasn't Tahrir Square. It was a small group of people who are very well paid and very well looked after, attacking another group of people who are very well paid and very well looked after."

To open up the City to greater scrutiny, Olisa is proposing a "good governance index", allowing funds to track those companies with the highest standards of boardroom behaviour.

"Anyone who cares about good governance would invest on that index," he says. "Companies wouldn't want to be in the non-top 100 good governance list, because you want to be in the most prestigious part of the stock exchange."

He even thinks a good governance index could have prevented the boardroom turmoil at ENRC. "If we had a good governance index in the UK, the founders of the ENRC would have done their best to be on it because that would have given them access to legitimacy and funds … Had they lost points in the good governance index they would have changed [their behaviour]."

He also reckons a governance index could bring greater diversity into the boardroom, far more effectively than "a deeply patronising" quota that is "humiliating for the target group".

"If you lost 10 points out of 150 for having all men aged above 60 on the board, you would do something about it," he says.

Olisa was brought up by a single mother in a rundown part of Nottingham. In 1970 he won an IBM scholarship to Cambridge, catapulting him into the city as the spirit of Paris '68 flared over the university's medieval courts and spires. "There was a general sense of social discontent and in my first term students occupied the senate house [used for degree ceremonies] and nobody did anything about it. I remember cycling to lectures and back again and it was scary because it seemed the world was out of control," he recalls.

His journey to Cambridge, supported by his mother and helpful teachers, was "totally an American-dream meritocratic model" at a time when there were very few black students at the university. It was an era when the appointment of a black bus conductor made the front page of the Nottingham Evening Post. "That is how far we have come in my lifetime in terms of tolerance and understanding."

His 18-year-old self "would be absolutely amazed" at where he is today: Olisa's alma mater, Fitzwilliam College, has just unveiled the Olisa library, funded for the most part by his £2m donation.

He insists that a poor student from Nottingham would have the same chances of getting to Cambridge today. Claims that the ladder of opportunity has been pulled away are wrong, he says. "Tuition fees are daunting but there are lots of countries where you pay for education and people still go to university and make things happen."

The universities are unjustly blamed, he thinks, for the failings of schools. "Access has got better. Cambridge didn't go out to find me in 1970. My school and I had to find Cambridge."

To this end, Olisa and the Powerlist Foundation that he chairs plan to launch a sixth-form free school in south London in 2015, targeted at developing leadership skills among poor students.

Should the students then choose to go into business, they will find a much more welcoming attitude to entrepreneurship than when he did in his first job at IBM in the 1970s. "I can remember when people left IBM to start their own business, we considered them to be spivs … This country has changed beyond all recognition in terms of willingness to embrace entrepreneurs."

Olisa's own journey as an entrepreneur started when he was fired from Wang Laboratories after the computer firm went bankrupt. In 1992 he launched Interregnum, a technology merchant bank, which floated on the stock exchange in 2000.

His interest in good governance also landed him a board seat on the MPs' watchdog, the Independent Parliamentary Standards Authority (Ipsa). But he won few friends on the green benches when he accused MPs of falsely complaining of sleeping in their offices because of expense policy reform.

Olisa, who clashed with speaker John Bercow and quit the IPSA board in 2011, does not think MPs deserve a big pay rise. In words that will inflame parliamentarians, he says: "MPs get £67,000 for a part-time job and they earn more than 90% of the population.

"There is no evidence [their pay] should be higher … It always annoys MPs when I say it is a part-time job. They say they are working 25 hours a day; well, so am I."

It is no surprise to him that the public are dissatisfied with Westminster and the City. "The common thread is dissatisfaction with the elite," he says. "Whether you are running a bank or running the country, if you are somehow self-anointed and consider yourself to be above and distant from anyone else that is increasingly irritating. We don't mind elites when they are qualified and humble."

Part of the answer goes back to the motto on his crest. "I'm grateful to what has happened in my life and if we don't make it happen for others we will have more schism."